PT - JOURNAL ARTICLE AU - Wan-Yuo Guo AU - Yu-Te Wu AU - Hsiu-Mei Wu AU - Wen-Yuh Chung AU - Yi-Hsuan Kao AU - Tzu-Chen Yeh AU - Cheng-Ying Shiau AU - D. Hung-Chi Pan AU - Yue-Cune Chang AU - Jen-Chuen Hsieh TI - Toward Normal Perfusion after Radiosurgery: Perfusion MR Imaging with Independent Component Analysis of Brain Arteriovenous Malformations DP - 2004 Nov 01 TA - American Journal of Neuroradiology PG - 1636--1644 VI - 25 IP - 10 4099 - http://www.ajnr.org/content/25/10/1636.short 4100 - http://www.ajnr.org/content/25/10/1636.full SO - Am. J. Neuroradiol.2004 Nov 01; 25 AB - BACKGROUND AND PURPOSE: Brain perfusion is disturbed by cerebral arteriovenous malformations (AVMs). Our study was conducted to determine the radiosurgical effects on this disturbed perfusion.METHODS: MR perfusion imaging with independent component analysis was performed in five healthy subjects and 19 patients with AVM before and after radiosurgery (every 6 months up to 2 years). Perfusion map relative cerebral blood volume (rCBV), cerebral blood flow (rCBF), and mean transient time (rMTT) were assessed. Regions of interest (ROIs) on AVM target sections were defined as follows: N, AVM nidus; H, the rest of the ipsilateral hemisphere; P, immediately posterior to the nidus; A, immediately anterior to the nidus; Ar, anterior remote; Pr, posterior remote. Similar ROIs in the contralateral hemisphere (N1, H1, P1, A1, Pr1, and Ar1) served as internal references. Perfusion ratios of ROI–ROI1 were defined. Nonparameteric Mann-Whitney U tests and generalized linear models were used for statistical analysis.RESULTS: Before radiosurgery, patients’ H/H1 rCBV and rCBF ratios were significantly higher than those of healthy subjects (P < .005), indicating AVM steal. Three types of perilesional perfusion disturbance were observed. From the first postradiosurgical follow-up at 6 months, N/N1 rCBV and rCBF ratios gradually decreased to 1.0 (both P < .001), whereas rMTT ratios gradually increased to 1.0 (P < .015); H/H1, A/A1, and P/P1 rCBV and rCBF ratios decreased after radiosurgery (P < .005), indicating reversal of steal toward normal perfusion.CONCLUSION: Initial high transnidal flow and perinidal perfusion disturbances were demonstrated. They gradually changed toward normal perfusion after radiosurgery. This explains, in part, the pathophysiologic factors of AVM and therapeutic effects.